Mounting system



E. J. OLOWINSKI MOUNTING SYSTEM Aug. 20, 1963 2 Sheets-Sheet 1 FiledAug. 8, 1961 I INVENTOR. WW}! 0M WWW M Aug. 20, 1963 E. J. OLOWINSKIMOUNTING SYSTEM 2 Sheets-Sheet 2 Filed Aug. 8, 1961 FIG. 5

INVENTOR.. Maw/w 3,101,228 MOUNTlbIGr SYSTEM Edward J. Olowinski,Erie,--la., assignor t'o'Lord Manufacturing Company, Erie, Pa., acorporation of Pennsylvania Filed Aug. 8, 1961, Ser. No. 130,171 10Claims. (Cl. 312-352) This invention is a mounting system for protectingsensitive equipment from shock, noise, and vibration. One use is inmobile ground equipment for missile control, some of which is sosensitive that when unprotected, its performance is affected by normalconversation in the immediate area.

In the drawing, FIG. 1 is a perspective of the mounting system, FIG. 2is a section through one of the mountings, FIG. 3 is a section throughone of the members for reinforcing and damping the enclosure for theequipment, FIG. 4 is a side view of the mounting system, and FIG. 5 isan end view of the mounting system.

'The principal parts of the mounting system consist of an acousticalenclosure 1, a base 2 in the form of two longitudinally extendingchannels, mountings 3 arranged at the four corners of the enclosure'tosupport the enclosure on the base, and a rack 5 on which-the equipmentto Y be. protected is mounted.

The acoustical enclosure -1 has spaced inner and outer sheet metal walls4=and 7 extending around the top, bottom and sides. The endsare closedby panels held [in place by nuts-8 and similanly'constructed with spacedinner and outer sheet metal walls *9 and 10. The space between the sheetmetal walls is filled with an elastomeric foam 'll-which fills all voidspaces between the walls and providesa damped connection between the.sheet metal walls andass-ists in making the enclosure an effectiveacoustical shield. Mechanical bracing of the walls of the enclosure isprovided by damped structural members 12 extending'peripherally aroundthe center of the enclosure and diagonally across the endpanels and oneither side of the center of the enclosure. These structural members.provide reinforcement and at the same time provide reinforcementwithout creating a metallicpath between inner and outer sheetmetal-walls, and with the introduction of damping :intothe compositestructure.

The structural members '12, as shown in FIG. 3, corn- 1 prise aninverted channel section lG and two single sections 14 with one sideflange 14a adjacent and extending up along one side of the channel andwith the other flange 14b extending outwardly away from the channel. Thesides 14a have a plurality of longitudinally spaced slots 15 extendingsubstantially the full height'of the sides of the channel.

Because of'the slots, the angleiseotions alone have little strength andtendto-bend about an axis close to the plane of the flanges 14b.Betweeneach of the flanges 14a and eachof the sides of thec-hannelsection is a layer 16 of highly dampedelastomeric material. This layeris bonded to the outside surface of the sides of the channel and is alsobonded to the adjacent surface of the flanges 14a. Wl1eninsta1led, theflanges 14b are attached to the. inner walls 4 and 9- and the bottom ofthe channel 13 is attached to the outer walls 7 andltl. The metallicenclosure walls are relatively light and non rigid sheet metal and havenumerous natural=modes of vibration at frequencies in the soundfrequency spectrum and at these frequencies tend to transmit, andmagnify sound which impinges on the walls. The magnification isincreased if any 1 of these frequencies correspond to natural modes ofvibration associated with the internal dimensions of the enclosure. Thetransmission is decreased by two expedients. First, the dampedstructural members 12 increase the rigidity and raise the naturalfrequenciesfiof the enclosure 3,101,228 PatentedAug. 20, 1963 above thecritical operating frequency range of 0-400 c.-p.s. The.structuralmembers 12 also provide damping which is effective forfrequencies in which the walls of outerand inner shells move in unisonas well as for higher frequencies which may produce some independence ofmotion. The members 12 do not reduce a large'scale vibration of theouter shell tosmaller motions of the inner.

Rather, the members'12 reduce the responseof the cornbined. structure,compared to'the vibration it would experience if undamped. Hence,conditions inside the box are improved. Thereis a further attenuation orabsorption of acoustical energy by the damping of the structure by thefoam 11. Gaskets18, also of highly damped elastomeric material,.arearranged between the removableend panels and the. endsof the housing.The result is an acoustical enclosure which has an attenuation averaging15 db throughout the entirev frequency band up to 2500 cycles persecond. The'attenuationis better than 15 db .throughout the.criticalopenating frequency range of zero to 10 0 cycles per second.

.x'l he-structuralmembers12are described in greater de- -.tail inapplication. Serial :No.820,448, filed June '15, 1959.

The acoustical .enclosure 1 is supported on the base members 2 bymountings3 arranged at the four corners of the enclosure. Each ofthesemountings, as shown in detail in FIG.:2, comprises a housing11'9attached to the base 1 channel2 and an upstanding post. 20, extendingout through a centeropening 21 in the top of the housing and suitablyattached to the acoustical enclosure. At the lower end of the post.20 isan enlarged head 22 embedded in abody v23 of highly damped el-astomerhaving upwardly and -.1 downwardly extending annular flanges 24 and 25above ,and below the head 2r2.and a radial flange 26 opposite the head.

spaced from the vertical wall 27 of a liner ;28-of elas- Inthe normalposition, the radial flange 26 is tomeric material. The lower flange 25is similarly spaced 1 above a horizontal Wall 29 of the liner .28 andtheupper --flange 24 is spaced belowa grommet 3-0 snapped over the edge ofthe opening 21 in the topwall of the housing.

The li-ner27 and grommet 28 are made of the same material as the body23-. While thereis normally no con- :tactbetween the flanges 24, 25 and26, and the adjacent Lparts of the; housing, upon excessive movement theflanges .do make.contact;and limit the movement. In each case,

the contact is between an elastomeric flange (24,25, 26-) and an.adjacent elastomeric part on the housing (30, G9,

The function of the body 23 and its associated yflanges is to limitexcessive excursion such as might occur --during shock or resonanceconditions. The vibration isorlation is effected by a coil spring 31having its lower end *seatedon aseat 32 on the bottom wall 3 3ofthehousing andhaving'its upper endseated on a seat 34 embedded in andbonded to the under side of the elastorneric body .23. The upper side ofthe spring seat 34 is spaced below .the head 22 so there is no directmetal-to-metal connection through which vibration and noise could betrans- 'mitted. The springs '31 are relatively soft so asto provide-goodvibration isolation. The fact that the flanges .24, 2'5 and 26 are outof contact with the internal walls of the housing is desirable for moreeffective vibration isolation. When-the flanges 24 to 26 doicome into.contact with the interior of the housing it is (for the purpose ofprotecting the supported enclosure 1 from shock.

; On opposite side walls of the acoustical enclosure 1 are opposedlongitudinally extending channels 35 slidab ly receiving the rack 5 onwhich the equipment to be protected is mounted. At the..four.corners ofthe rack are rubber mountings 37 which. provide avibrat-ion isolatingconnection from the equipmentrto. the rack. ,The mountings 37areprimarily for theisolationof high frequency 'vi- 1 bration. 'The-raekis held in its operatingposition by a releasable catch 38. The removableend panels of the housing have projecting prongs 39 which fitv incomplementary recesses in the ends of the rack and hold it in place.

A ground strap 40' extends between one of the base channels 2 and theacoustical housing. One wall of the acoustical housing is provided withelectrical connectors 41 through which connection is made to theequipment inside the housing.

What is claimed as new is:

1. A mounting system comprising an acoustical enclosure having spacedinner and outer metal walls and a structural connection between thewalls including a highly clamped elastomer, a rack within and supportedby the enclosure, elastomeric mountings on the rack for supportingequipment within the enclosure, a plurality of mountings for supportingthe enclosure each comprising a hous ing having top, bottom and sidewalls with an opening in the top wall, a member extending out throughsaid opening and connected in load carrying relation into saidenclosure, a coilspring having spring seats at upper and lower ends, thelower of the spring seats being on the bottom wall of the housing, abody of highly damped elastomer within the housing having projectingflanges normally spaced from the walls of the housing so as to contactthe Walls and limit the excursion during shock but not to contact thewalls during the normal excursion during vibration, the upper seat beingbonded to said body, and said member being embedded in and bonded tosaid body in spaced relation to said upper spring seat.

2, A mounting system comprising an acoustical enclosure having soundattenuating walls blocking external sounds from the interior of theenclosure, elastomeric mounting means within the enclosure forsupporting equipment, said means being proportioned to isolate highfrequency vibration from the supportedequipment, a plurality ofmountings for supporting the enclosure each comprising a soft springproportioned to isolate low frequency vibrations, a base, a loadcarrying connection from one end of the spring to the base, a loadcarrying connection from the other end of the spring to the enclosure,said last mentioned connection including an elastomeric section, andsnubbing means having elastomeric parts respectively connected to thebase and to the enclosure and spaced from each other during the normalexcursion of the enclosure relative to the base during vibration andcoming into contact with each other to limit the larger excursion of theenclosure relative to the base during shock.

3. A mounting :system comprising an acoustical enclosure having soundattenuating walls blocking external sounds from the interior of theenclosure, vibration isolating means within the enclosure for supportingequipment within the enclosure, a plurality of mountings for supportingthe enclosure each comprising a housing having top, bottom and sidewalls with an opening in the top wall, a member extending out throughsaid opening and connected in load carrying relation into saidenclosure, a coil spring having spring seats at upper and lower ends,the lower of the spring seats being on the bottom wall of the housing, abody of highly damped elastomer within the housing having projectingflanges normally spaced respectively from the top, bottom and side wallsof the housing so as to contact the walls and limit the excursion duringshock but not to contact the walls during the normal excursion duringvibration, the upper seat being bonded to said body, and said memberbeing embedded in and bonded to said body in spaced relation to saidupper spring seat.

4. A resilient mounting comprising a housing having top, bottom and sidewalls with: an opening in the top wall, a member extending out throughsaid opening and for connection to a load, a coil spring having springseats at upper and lower ends, the lower of the spring seats being onthe bottom wall of the housing, a body of highly damped elastomer withinthe housing having projecting flanges normally spaced from the walls ofthe housing so as to contact the walls and limit the excursion duringshock but not to contact the walls during the normal excursion duringvibration, the upper seat being bonded to said body, and said memberbeing embedded in said body in spaced relation to said upper springseat.

5. A resilient mounting comprising a housing having top, bottom and sidewalls with an opening in the top wall, a member extending out throughsaid opening for connection to a load, a coil spring having spring seatsat upper and lower ends, the lower of the spring seats being on thebottom wall of the housing, an elastomeric lining for the housing, abody of highly damped elastomer within the housing having projectingflanges normally spaced respectively from the lining so as to contactthe lining and limit the excursion during shock but not to contact thelining during the normal excursion during vibration, the upper seatbeing embedded in said body, and said member being embedded in said bodyin spaced relation to said upper spring seat.

6. A resilient mounting comprising a housing having top, bottom and sidewalls with an opening in the top wall, a member extending out throughsaid opening for connection to a load, a coil spring having spring seatsat upper and lower ends, the lower of the spring seats being on thebottom wall of the housing, a body of highly damped elastomer within thehousing having a plurality of annular flanges respectively projectingupwardly, downwardly land outwardly from said, body and respectivelynormally spaced from the walls of the housing so as to contact the wallsand limit the excursion during shock but not to contact the walls duringthe normal excursion during vibration, the upper seat being bonded tosaid body, and said memberbeing embedded in said body in spaced relationto said upper spring seat.

7. A mounting system comprising an acoustical enclosure having soundattenuating walls blocking external sounds from the interior of theenclosure, means within the enclosure for supporting equipment to beprotected, a plurality of mountings for supporting the enclosure eachcomprising a coil spring having spring seats at upper and lower ends, asupporting member carrying the lower spring seat, a body of highlydamped elastomer carrying the upper spring seat, a load carryingconnection from the elastomer to the enclosure, said connection beingspaced from the upper spring seat, and a structure spaced from theelastomer under the normal excursion during vibnation and havingsurfaces coming into engagement with the elastomer under the largerexcursions during shock for limiting such excursion.

8. A mounting system comprising an acoustical enclosure having soundattenuating walls blocking external sounds from the interior of theenclosure, means within the enclosure for support-ing equipment to beprotected, a plurality of mountings-for supporting the enclosure eachcomprising a coil spring having spring seats at upper and lower ends, asupporting member carrying the lower spring seat, a body of highlydamped elastomer carrying the upper spring seat, a load carryingconnection from the elastomer to the enclosure, said connection beingspaced from the upper spring seat, and a structure spaced from theelastomer under the normal excursion during vibration and havingsurfaces coming into engagement with the elastomer under the largerexcursions during shock for limiting such excursion, and a coating ofhighly damped elastomer on said surfaces for absorbing energy of impact.

9. A mounting system comprising an acoustical enclosure having soundattenuating walls blocking external sounds from the interior of theenclosure, means within a? enclosure for supporting equipment to beprotected, vibration isolating means for supporting the enclosurecomprising a soft spring means proportioned to isolate spaced irom theupper spring sea-t, and a structure spaced from the elastomer under thenormal excursion during load carrying connection firom the other end ofthe spring to the enclosure, said last mentioned connection including anelastorneric section, and snubbing means including elas-tom'eric partsrespectively connected to the base and to the enclosure and spaced fromeach other during the normal excursion of the enclosure relative to thebase during vibration and coming into contact with each other to limitthe larger excursion of the enclosure relative to the base during shock.

10. A resilient mounting comprising a coil spring having spring seats atupper and lower ends, a supporting member carrying the lower springseat, a body of highly damped elastomer carrying the upper spring seat,a supported member, a load carrying connection from the elastomer to thesupported member, said connection being vibration and having surfacescoming into engagement with the elastomer under the larger excursionsduring shock for limiting such excursion.

References Cited in the file of this patent UNITED STATES PATENTSAustralia Apr. 4, 1940 g

9. A MOUNTING SYSTEM COMPRISING AN ACOUSTICAL ENCLOSURE HAVING SOUND ATTENUATING WALLS BLOCKING EXTERNAL SOUNDS FROM THE INTERIOR OF THE ENCLOSURE, MEANS WITHIN THE ENCLOSURE FOR SUPPORTING EQUIPMENT TO BE PRETECTED, VIBRATION ISOLATING MEANS FOR SUPPORTING THE ENCLOSURE COMPRISING A SOFT SPRING MEANS PROPORTIONED TO ISOLATE LOW FREQUENCY VIBRATION, A BASE, A LOAD CARRYING CONNECTION FROM ONE END OF THE SPRING MEANS TO THE BASE, A LOAD CARRYING CONNECTION FROM THE OTHER END OF THE SPRING TO THE ENCLOSURE, SAID LAST MENTIONED CONNECTION INCLUDING AN ELASTOMERIC SECTION, AND SNUBBING MEANS INCLUDING ELASTOMERIC PARTS RESPECTIVELY CONNECTED TO THE BASE AND TO THE ENCLOSURE AND SPACED FROM EACH OTHER DURING THE NORMAL EXCURSION OF THE ENCLOSURE RELATIVE TO THE BASE DURING VIBRATION AND COMING INTO CONTACT WITH EACH OTHER TO LIMIT THE LARGER EXCURSION OF THE ENCLOSURE RELATIVE TO THE BASE DURING SHOCK. 